Nova

Nova is a power for Vanguards in Mass Effect 3. Nova is a close-range shock wave power which utilizes the Vanguard's high-risk, high-reward combat system. While expending the remainder of your biotic barrier, Nova inflicts a high amount of damage to surrounding enemies, pushing them back and sending them soaring into the air. There is no cooldown--it can be used whenever the Vanguard has barrier remaining.

Nova is the Vanguard's counterpart to a grenade ability; that is, it neither triggers nor works off ability cooldown.

The Nova is a brilliant way to finish a Biotic Charge, if you are not using such for defensive purposes or escape. The Charge will stun or kill the first enemy you hit, and following so with a Nova annihilates other enemies not caught in the original blast.

In addition, Nova can be used in succession with Biotic Charge and Heavy Melee to deliver a devastating "1-2-3" power combination punch, where a player can follow a Biotic Charge with a Nova attack and finish off heavily armored or shielded enemies with Heavy Melee. The combination has become popular, and is ideal for clearing out tightly packed enemies in seconds.

The reverse is also highly effective. When in close proximity Nova can be used to stun opponents and followed up by a Biotic Charge, which replenishes your shields, thus taking some of the risk out of using the Nova. In addition, it also opens up the option for unleashing a second Nova, which can have a devastating effect on remaining enemies.

If Biotic Charge is evolved specifically for speed instead of area of effect, and used in tandem with a lighter weapon, Biotic Charge can be regularly alternated with Nova. The near-instant cooldown of both abilities mitigates the risk of charging to a negligible level, and renders a properly evolved Vanguard as an incredibly powerful damage dealer on the battlefield.

During the Nova animation, the player is invulnerable to non-execute attacks with the exception of a Ravager's cannon blast. This can be used to buy time for Charge to cooldown, and you can dodge cancel it if you want to save the barriers.

The timing to perform a dodge cancel is to dodge in any direction (more reliable sideways), just as the Vanguard is at the "peak height" of the animation. Poor timing will either result in player not receiving any invulnerability frames from the Nova-Cancel, or the player's barriers will be used/depleted.

The Rank 5 Half Blast evolution can be used effectively too. The reduced consumption will reduce your damage by 40%, but as compensation, if you are overwhelmed by enemies at longer ranges than your Nova will hit, you can make a quick getaway if everything hits the fan. Conversely, it can also be used to polish any enemies that are still left standing after the initial blast--this will guarantee you eliminating weaker enemies from the fight as well as inflicting significant damage on stronger enemies. If cooldown is low enough, you can initiate two half blasts, then Charge immediately afterwards, allowing for a near constant supply of barriers, and a brutally high level of damage.

In Single-player, after the shields are depleted by Nova, you are able to sustain one hit before health starts taking damage from enemy fire. This is because the "bullet time" effect from shield depletion still has yet to occur unless triggered by enemy fire.